Karin Ward is relieved this year is coming to an end. "Oh God, yeah," she says. "It's been hell. Absolute hell."

Over the past 12 months, Ward has been catapulted into the media spotlight after unwittingly triggering one of the biggest news stories of recent times. It was Ward who, when approached by Newsnight in late 2011, reluctantly agreed to a taped interview in which she alleged she had been molested by the late TV presenter Jimmy Savile as a teenager. Ward was the first of Savile's alleged victims to speak out. But the Newsnight report was shelved in December. Ten months later Ward appeared in the ITV documentary Exposure: The Other Side of Jimmy Savile, leading to accusations that the BBC had abandoned their report in order to avoid a scheduling conflict with planned commemorative tributes to Savile.

When the existence of the Newsnight investigation became public, the BBC found itself in crisis. Key figures in the corporation "stepped aside" as the management struggled to control the fall-out. Several hundred more victims came forward to claim Savile had abused them. Then, as a consequence of a Newsnight report, the former Conservative party treasurer Lord McAlpine was wrongly linked to historic allegations of child sexual abuse. As a result, on 10 November, George Entwistle resigned as BBC director general.

And at the centre of it all is Karin Ward, a 54-year-old mother of seven who lives in the village of St Martins, near Oswestry on the Welsh borders.

"I can't quite believe I actually triggered it," she says when we meet over coffee in a nearby hotel. She looks at me as if from a distance, her expression removed and her words curiously unemotional. It is, one suspects, a defence mechanism, mastered in order to cope with repeatedly being asked to relive a traumatic personal past for public consumption.

"In a purely selfish way, I was actually glad so many other people stepped forward and said 'And me', because I'd been vindicated. For years, I'd told the truth and been accused of being a troublemaker or an attention-seeker."

Ward had a troubled childhood which she says was punctuated with episodes of sexual abuse. By the age of 14, she was a pupil at the Duncroft approved school for girls in Surrey where Savile was a regular visitor. He would, she says, turn up in his Rolls-Royce, distributing sweets and cigarettes in return for sexual favours. On several occasions, girls from Duncroft were bussed to London to appear on Savile's Saturday night variety show, Clunk Click, filmed at BBC Television Centre. In his dressing-room after filming, Ward alleges, the abuse continued.

"He was a dirty old man who had a liking for very young girls," Ward says now. "His hands were always up your skirt or your top and if you were wearing trousers, he'd find a way to slip them down your waistband. He just couldn't keep his hands to himself.

"None of us saw it as abuse [at the time]. We used to giggle about who did what to him. We'd giggle and then smoke the fags he gave us. He was very charismatic, if in a kind of creepy and weird way. But when you're a teenager, you get swept along with it, you've got stars in your eyes. If he asked you to do something horrible, it was par for the course. You know, you've got to stick with him because you might get on the telly."

Years later, a psychologist suggested Ward write about her experiences as therapy. She did so, then published the manuscript online with Savile referred to only by his initials. It was this manuscript that led the Newsnight reporters to her door. Initially, Ward, who was undergoing treatment for bowel cancer, was unwilling to co-operate. Eventually, she agreed. Why did she change her mind?

"Because I was so convinced of two things," she replies. "Number one: I was 100% convinced that the interview would never be broadcast. I knew the BBC wouldn't allow it. I knew it in my bones that there were so many high-ups who wouldn't let it go ahead. Number two: I was 100% convinced that I wasn't going to survive [bowel cancer] surgery."

As it turned out, she was wrong about the surgery but right about the BBC. The producer of the Newsnight film, Meirion Jones, let her know by text that the programme was not going to be aired because he was – believes Ward –"terminally embarrassed" and couldn't bring himself to speak to her in person.

To begin with, Ward wasn't particularly upset: "And then, as the day of my operation grew closer, I got more stressed and angry at the BBC. I actually managed to avoid obsessing about the operation because I was obsessing about what bastards the BBC had been," she laughs. "So in a way, I thought: they did me a favour."

The operation was a success but her recovery was a slow and painful one – Ward now has to cope with a stoma, which she describes as "horrible". Throughout it all, she has had to put up with reporters hounding her on an almost daily basis. These days, she reserves most of her ire not for Jimmy Savile but for the BBC. What did she feel when Entwistle resigned?

"I felt it was too little, too late and it's the wrong people. The director general? This guy has only been in the job for a few months! What's the point of sacking him? Who was the director general 40, 50 years ago? Because sure as eggs is eggs, he knew about it. Everybody knew what Jimmy Savile was like – it was a kind of open secret."

At the last count, 450 of Savile's alleged victims had come forward to police. Ward is now pursuing her own legal action for historical abuse but thinks this number represents "about 10% [of the true victims]."

Is she still angry at Savile?

"It's kind of strange. The other victims seem very angry. I'm not aware of feeling angry now … I'm left with his underlying melancholy. I don't find the joy I think I should find in life." She says this without self-pity but rather as simple fact; one that is finally, after all these years, worth acknowledgement.